Vibrationless engines



' p 24, 6 P; HERON 3,402,707

Y-IBRAT IONLESS ENGINES Filed Sept. 18. 1964 7 Sheets-Sheet 1 4 Mme-2. 1I a i Sept. 24, 1968 Filed Sept. 18. 1964 O In P. HERON VIBRATIONLESS-EIIGIIIES "(Sheets-sheaf. 2

Sept. 24, p HERON VIBRATIONLESS ENGINES Filed Sept. 18, 1964 7Sheets-Sheet 4 Filed Sept. 18, 1964 muFZDOU QUE vow M Sept. 24, 1968' P.HERON 3,402,707

VIBRATIONLESS ENGINES Filed Sept. 18, 1964 7 Sheets-Sheet 5 FLEXIBLECOUPLING TO LOAD Qua/W FIG-.6

pt- 24, 1968 P. HERON 3,402,707

. VIBRAT IONLESS ENGINES Filed Sept. 18, 1964 7 Sheets-Sheet e HYDRAULICTORQUE- CONVERTER Sept. 24, 1968 P. HERON 3,402,707

VIBRATIONLESS ENGINES Filed Sept. 18, 1964 7 Sheets-Sheet '7COUNTER-FLYWHEEL TWISTY SHAFT COUNTER-FLYWHEEL PROPELLER United. StatesPatent 3,402,707 VIBRATIONLESS ENGINES Paul Heron, 309 Riverside Drive,

. Oakville, Ontario, Canada Continuation-impart of application Ser. No.140,972, Sept. 21, 1961, which is a continuation-in-part of applicationSer. No. 366,927, July 9, 1953. This application Sept. "18, 1964, Ser.No. 397,587 29 Claims. (Cl. 123-192) The following specification is acontinuation-in-part of an earlier application, Ser. No. 140,972, filedon Sept. 21, 1961, which, in turn, was a continuation-in-part of a stillearlier application, Ser. No. 366,927, filed on July 9, 1953.

These inventions and the mechanical principle discovered in them arechiefly concerned with internal combustion engines, such as gasoline anddiesel engines, in which power is created by a series of explosions thatact on one or more pistons that move in cylinders and are connected toand turn a crankshaft. The main object of these inventions is toeliminate the vibration that is generally caused in such engines by theseries of explosions, and the mechanical principle that has beendiscovered is a law of motion that teaches how vibration cantheoretically be eliminated completely from any kind of engine orcompressor or similar machine.

Another object of these inventions is to reduce the cost of engines,particularly small and medium-size diesel engines, by making itpractical to use engines with fewer (although larger cylinders. Onelarge cylinder is cheaper than two small ones, particularly if they havediesel fuel injection equipment.

Among the more specific objects of these inventions are to make dieselengines really practical for automobiles, light trucks and smalltractors, to provide little electric generating sets for boats and housetrailers etc. that will not annoy people by their vibration, and toeliminate the vibration from such things as chain saws, scooters, motorbicycles, and small airplanes.

There are four principal sources of vibration in gasoline and dieselengines: (1) The moving parts of the engine may not be in ordinarystatic and dynamic balance, and this causes the engine to vibrate bodilyup and down or from side to side or to rock or twist about its center ofgravity. (2) The moving parts of the engine, such as the crankshaft, maybend or twist when the engine is running, and this spoils the balance ofthe moving parts and so causes vibration. (3) The frame or crankcase ofthe engine may not be stiff enough to resist the explosion or inertiaforces in the engine without bending appreciably, and so the variationin these forces causes the frame or crankcase to vibrate. (4) Thesuccessive explosions in the cylinders, that push the pistons down andturn the crankshaft, act also on the cylinders and the engine block orframe and make it vibrate. The first of these sources of vibration(unbalance) can be practically eliminated by providing several cylindersand pistons and arranging these about the crankshaft so that the'pistons balance each other, as in ordinary sixcylinder in-line enginesor ordinary V-eight engines, or are balanced by counterweights on thecrankshaft, as in ordinary radial aircraft engines. This source ofvibration can also be practically eliminated in four-cylinder inlineengines by using the balancer invented by Dr. F. W. Lanchester and shownin his U.S. Patent No. 1,163,832, and it can be completely eliminated inone-cylinder and two-cylinder in-line engines by using the balancerinvented by Sir Harry Ricardo and shown in his U.S. Patent No.1,310,090. Many other ways of eliminating this source of vibration havebeen devised, and whole books have been written on the subject. It iswell understood by good engine designers.

The second source of vibration (distortion of the moving parts of theengine) can be practically eliminated by making those parts very stiff,like the short heavy crankshafts in V-eight automobile engines. If someparts, such as the long crankshaft in a six-cylinder in-line engine,cannot be made stiff enough, the vibration from this source can be keptsmall enough to be unnoticeable by dampers like the one invented by Dr.F. W. Lanchester and shown in his U.S. Patent No. 1,085,443.

The third source of vibration (bending or twisting of the frame orcrankcase of the engine) can be practically eliminated by making thecrankcase or frame stiff enough. The necessary stitfness can be securedby using more metal in the frame or crankcase, changing the design sothat the metal carries the forces more directly, or by using a stiffermetal, such as steel in place of cast iron or aluminum.

The fourth source of vibration (the successive explosions in thecylinders) is the one with which the present inventions and discoveryare concerned. Until nOW, practically the only ways in which vibrationfrom this source have been lessened are (1) by making engines heavy, and(2) by making engines with many cylinders, with as many as sixteencylinders in certain American automobiles in the late 1920s. Theadoption of flexible mountings for automobile engines in the early 1930spermitted those engines to vibrate a moderate amount without too much ofthe vibration being transmitted to the driver and passengers. and twelveand sixteen cylinder engines soon became obsolete. But the amount ofvibration that can be insulated by flexible mountings is limited. Inordinary automobiles today, the vibration of a six-cylinder engine canbe felt at low engine speeds, and eight has become the standard numberof cylinders for American automobiles. In less wealthy parts of theworld, most automobile users put up with the vibration from six-cylinderand four-cylinder engines, some with two-cylinder engines, and some evenwith one-cylinder engines in tiny cars and scooters. In small airplanes,six-cylinder engines have become almost standard in order to keep thevibration down to tolerable levels, even though engines with fewer largecylinders would be cheaper to buy and to run.

These inventions deal with this fourth source of engine vibration (thesuccessive explosions in the cylinders) in a different Way. They do notmerely lessen it, as does the use of many cylinders, nor do they make itmerely tolerable, as does the use of flexible engine mountings. Theseinventions virtually eliminate that vibration right in the engineitself; they make the engine practically vibrationless, like an electricmotor or a steam or gas turbine. In some of these new inventions, thisis done by balancing, Within the engine, all of the forces left tovibrate the engine. In others, it is done by combining the engine withan electric generator or with a pump or compressor and then balancing,within the engine-andgenerator or engine-and-pump orengine-and-compressor, all of the forces exerted by the explosions sothat there are no unbalanced forces left to vibrate the combinedmachine. In others, it is done by having the engine drive apower-transmitting device (like a marine or airplane propeller or theimpeller of a centrifugal pump or blower) that is free to vibrate withthe power impulses transmitted to it and that has a moderate moment ofinertia or flywheel effect and then balancing, within the assembly ofthe engine and the propeller or impeller, all of the forces exerted bythe explosions, except the practically constant reaction of the water orair or other fluid on the propeller or impeller, so that there are nounbalanced forces left to vibrate the engine. In still others, it isdone by combining the engine with some power-transmitting device (suchas a hydraulic coupling or torque converter,

electro-magnetic coupling, or resilient coupling) that allows the poweroutput shaft of the engine to vibrate with the power impulses'created bythe explosions in the engine while exerting a practically constanttorque reaction on the power output shaft and then balancing, within theassembly of the engine and the part of the power-transmitting devicefixed to the power output shaft, all of the forces exerted by theexplosions except the reaction of the power-transmitting device, so thatthere are no unbalanced varying forces left to vibrate the engine.

In each of these new engines, the invention consists in having themoving parts in balance in the three principal linear directions(up-and-down, side-to-side, and front-to-back) and in balance in thethree principal rotational directions (about the longitudinal horizontalaxis, about the transverse horizontal axis, and about the vertical axis)and in having some way of taking the power from the engine in some sortof smooth flow that does not react back on the engine and vibrate it.

There is one broad principle that underlies the vibrationless running ofall these engines. That principle is this:

The frame or body of a machine will not vibrate if that frame or body isrigid and if (1) the algebraic sum of the momentum of all the movingparts in and on the machine in each of three directions at right anglesto each other is always zero, (2) the algebraic sum of the angularmomentum of all the moving parts in and on the machine about each ofthree different axes at right angles to each other is always zero, and(3) the machine does not exert a vibrating force or torque on anythingoutside itself and nothing outside of it exerts a vibrating force ortorque upon it.

This principle is stated above in terms of momentum, which is theproduct of mass and velocity. It can also be stated in terms of mass andrelative velocities, as follows, and it is then sometimes easier tounderstand and apply:

The frame or body of a machine will not vibrate if that frame or body isrigid and if (1) the center of gravity of the moving parts of themachine moves neither vertically nor longitudinally nor transversely,(2) the algebraic sum of the moments of inertia of all the moving partsof the machine about each of the vertical and transverse andlongitudinal axes of the machine, multi plied by their relativerotational speeds about those axes is zero, and (3) the machine does notexert a vibrating force or torque on anything outside itself, andnothing exerts a vibrating force or torque upon it.

In ordinary engines that are supposed to be well balanced, the first ofthese three main conditions is met. In an upright six-cylinder engine,for example, the momentum of the pistons and connecting rods moving downis balanced by the momentum of those moving up, and the algebraic sum oftheir momentum up and down is zero. Similarly, the momentum of the bigends of some of the connecting rods moving towards one side is balancedby the momentum of the big ends of the other connecting rods movingtowards the other side, and the algebraic sum of their momentum sidewaysis zero. Nothing moves endwise of the engine, so the momentum of themoving parts in that direction is zero. But the second of these threemain conditions is only partly met. Since this engine is symmetricalabout a plane perpendicular to the axis of the crankshaft at its center,the angular momentum of the moving parts on one side of that plane abouteither a vertical or a horizontal axis in that plane will be balanced bythe angular momentum of the similar moving parts on the other side ofthat plane, and the algebraic sum of their angular momentums abouteither of those two axes is zero. But the algebraic sum of their angularmomentums about the axis of the crankshaft is not zero; the crankshaft,the counterweights, the big ends of the connecting rods, the flywheel,and perhaps even the camshaft all turn in the same direction, and theirangular momentums all add up to a'large quantity when the engine isrunning. Thus the second of these three main conditions is not met in anordinary engine. The third of these three main conditions may or may notbe met, depending upon what the engine drives and how it drives it. Ifthe engine drives the rear wheels of an automobile through a frictionclutch, a gear box, a propeller shaft, and a rear axle, it exerts avibrating torque upon the propeller shaft and rear axle, and thereaction to this will vibrate the engine. However, if it drives the rearwheels of an automobile through an automatic transmission that includesa torque converter, as most such transmissions do, the torque exerted bythe impeller in the torque converter will be practically constant over ashort period of time, and the third condition will be met. However, thefailure to meet the second condition will be a source of vibration.

Although this fundamental principle of balancing engines and othermachines was not discovered until recently, a few engines which embodiedit, or came close to embodying it, had previously been conceived, andsome had been made. The earliest was probably Dr. F. W. Lanchesterstwo-cylinder balanced automobile engine of 1896, shown in his US. PatentNo. 613,769 and described in detail in the Dec. 9, 1955, issue of theLondon Autocar. In that engine, the masses and moments of inertia werepractically all balanced in all directions, thus meeting the first twoof the three main conditions stated above, but the engine exerted avarying torque on the shaft that transmitted its power to the gearboxand rear axle, and the reaction to this torque must have vibrated theengine when it was driving the automobile. However, when the engine wasidling, this varying torque and its reaction were absent, and the engineis reported to have been practically vibrationless then.

Engines with complete or almost complete balance both linearly androtationally (as in Lanchesters engine) but with the power take-offbalanced so that the reactions to the varying torques exerted by theengines would not vibrate them are shown in the US patents to I. W.Cloud (No. 968,127), H. Lemp .(No. 1,471,901), and P. Heftler (No.2,255,773). In each of these engines, there are two crankshafts turningin opposite directions, and the pistons are arranged in pairs withcommon combustion chambers so that the inertia forces and explosionforces are all practically balanced. Clouds engine would not be incomplete balance vertically, but that unbalance could easily be curedwith a Lanchester balancer. Lemps engine, if it were built as it wouldbe designed by a skilled engineer who did not know what is disclosedhere, would be somewhat out of balance because the two crankshafts wouldbe connected out of phase in order that the exhaust ports at one end ofeach cylinder would be uncovered before the intake ports at the otherend; this would put the pistons only a little out of balance because thefour pistons on each crankshaft balance each other fairly well, but thecrankshaft that would be ahead of the other would get most of the powerfrom each explosion and momentarily accelerate more than the other, andthis would destroy the rotational balance of the engine. Heftlers firstengine, which is otherwise similar to Lemps, avoids this unbalance byhaving the two crankshafts connected positively and in phase. Both ofHeftlers engines are theoretically in practically perfect balance(except for the valve gear and perhaps the accessories) and should bepractically vibrationless.

The important thing about Clouds, Lemps and Heftlers engines is that thetwo crankshafts of each engine delivered their power to devices thatcould absorb rotational vibration from the crankshafts withouttransmitting it to any other part of the structure. Clouds engine drivetwo airplane propellers which, if they were turned jerkily, merelystirred up the air a little more. Lemps engine drove two electricgenerators which, if they were turned jerkily, merely producedalternating current that was not pure sine-wave in its alternations.Heftlers engine drove through two hydraulic couplings, which areremarkably efficient'devices for averaging out torque and eliminatingvibration from power transmitted by them, so the power thatcame out fromthem was vibrationless.

However, these engines, which were in good balance both linearly androtationally and which delivered their powerto devices which couldabsorbthe rotational vibration caused by successive explosions, had onegreat fault: Having two crankshafts and two propellers or two generatorsor two hydraulic couplings and gear boxes, they were complicated'andexpensive. The new inventions described hereare vibrationless engineswith only one crankshaft andonly one device for taking. the power fromthe crankshaft without transmitting its vibration to any other part ofthe structure. The important discovery involved in these inventions isthat it is not necessary to have a symmetrical arrangement of movingparts in the engine in orderto'balance out the vibrating forces; allthat is necessary is that the moving parts of the engine and the part ofits load that is fixed to or geared to its crankshaft be in balance bothlinearly in the three principal directions (front-to-back,"side-to-side,and up-and-down)) and rotationally about axes extending in those threedirections and that the power of the engine be absorbed or transmittedwithout the vibrations in that power being reflected back into theengine.

It is important that the part of the load fixed to or geared to itscrankshaft be included in the balancing of the engine. Such a part ofthe load (like a propeller or the rotor'of an electric generator or theimpeller of a hydraulic coupling or torque converter) acts like aflywheel on the engine, and, together with the crankshaft and otherrotating parts, it must be balanced rotationally by a mass rotating inthe opposite or contrary direction. Such amass is called acounter-flywheel, and the principal invention disclosed here is simplythe addition of a counter-flywheel of the right size, to an ordinaryengine that drives'a load" whose mass fixed to or geared to thecrankshaft of the engine is small enough to be balanced by acounter-flywheel of reasonable size. When the engine drives a heavyload, like an automobile, the greater part of that load must beconnected to the crankshaft of the engine only by some device, such as ahydraulic coupling or torque converter, that allows the crankshaft tovibr-ate'rotationally without vibrating most of the load; then the partof the load fixed to the crankshaft, such as the'input elementof thehydraulic coupling or torque converter; is light enough, along with thecrankshaft and other parts in the engine, to be balanced rotationally bya practical counter-flywheel. Countenfiywheels are not new; one isshown, for example, on a one-cylinder engine in E. Ryders US. Patent,No. 2,407,102. What is new is the combination of 1) a load havinga'limited mass fixed or geared to the crankshaft of an engine and (2) acounter-flywheel on the engine'big enough to balance that mass inaddition to the masses of the crankshaft and other parts turning withthe crankshaft.

Down to this point, only engines with crankshafts have been discussed.However, the method of balancing engines disclosed here can beapplied'to other types of engines, such as those in which the pistonsact on a swashplate or a cam and even to'those in which there are nopistons. More importantly, this method of balancing can be applied tocompressors andpum'p-s and to combinations of engines and compressors'orpumps. Especially promising applications, besides engines, arerefrigeration compressors, particularly those combined with their ownsmall engines and used for cooling or air-conditioning the interior ofvehicles used for transporting food or people.

7 However, the greatest importance of these inventions seems to be thatthey will probably make the small diesel engine much more practical.Many tests have shown that an automobile or light truck with a dieselengine will go about twice as far on a gallon of fuel as a similar onewith a gasoline engine, but very few such vehicles are equipped withdiesel engines. That is because diesel engines are much more expensivethan gasoline engines and because they vibrate much more. Six-cylinderdiesel engines are too expensive to be used at all in automobiles andlight trucks, so four-cylinder ones are used. These are still tooexpensive to be used much, and, because of their much higher cylinderpressures, they vibrate more than four-cylinder gasoline engines andmuch more than V- eight gasoline engines. But, with these inventions,diesel engines for automobiles and light trucks, with only one or two orthree cylinders, can probably be made to vibrate less than the presentV-eight gasoline engines, and, having so few cylinders, they willprobably be as cheap or cheaper than the present gasoline engines withfour, six, or eight cylinders. Then diesel engines with these inventionsmay make large and medium-size gasoline engines obsolete.

Some of the different ways in which the inventions described broadlyabove can be used in engines, compressors, and combinedengine-compressors are illustrated by specific examples describedfurther on in this specification. These are only examples, and goodengineers who learn what is disclosed in this specification will be ableto design many other engines and other machines working according to theprinciple disclosed here and using one or more of the inventions.

In the drawings accompanying this specification,

FIGURE 1 is a plan view of the main rotating parts of a one-cylinderengine-generator set embodying the present discovery;

FIGURE 2 is a section on the line II--II in FIG- URE 1;

FIGURE 3 is a plan view of the main moving parts of a one-cylinderdiesel engine-generator set embodying the present discovery and inalmost theoretically perfect balance; and

FIGURE 4 is a plan view of the main moving parts of a combinedengine-compressor embodying the present discovery and in almosttheoretically perfect balance.

FIGS. 5-10 are illustrations of additional embodiments of the presentinvention.

The generating set illustrated in FIGURES l and 2 consists of aone-cylinder four-cycle gasoline engine and an electric generator withthe rotor 1 of the generator mounted on an extension of the crankshaft 2of the engine. The crankshaft is carried by its journals 3 and 4 intapered roller bearings, like the crankshaft in the Wisconsin AGHengine, and all of the parts of this engine that are not necessarilydifferent are taken from that engine. Pressed and keyed onto thecrankshaft, between the front journal and the front crankweb, is a maingear 5 that drives two similar gears 6 and 7 mounted on twocountershafts 8 and 9 located at either side of the crankshaft. Thecountershafts are mounted on bearings like those of the crankshaft butsmaller, and they extend out through the front of the crankcase andcarry counter-flywheels 10 and 11. The main flywheel of the engine isformed by the rotor 1 of the generator, pressed onto the rear end of thecrankshaft, which is made with a standard S.A.E. taper so that the rotorcan be removed from the crankshaft and the rear main bearing can beremoved, if necessary for servicing. One of the countershafts carries agear 12 for driving a gear twice its size on the camshaft, which islocated above and to one side of the crankshaft in the usual position.

The crankshaft carries counterweights 15 and 16 which are heavy enoughto balance all the weight of the crankthrow and the big end of theconnecting rod 17 and half of the weight of the little end of theconnecting rod, the wrist pin, and the piston and its rings. The twocountershafts carry fiyweights 20 and 21 which are heavy enough tobalance the other half of the weight of the little end of the connectingrod, the wrist pin, and the piston and its rings. These fiyweights liein the same transverse plane as the crankpin and connecting rod, andthey swing in between the counterweights on the crankshaft as they allrotate and swing out of the way when the connecting rod comes around.The countershafts have large notches 22 and 23 on the sides opposite theflyweights to provide clearance for the big end of the connecting rod 17as it swings around on the crank, and the strength and stiffness lost bythenotches is made up by increasing the diameter of the central portionsof the countershafts. The engine could be made without notches in thecountershafts, but they permit the engine to be made more compact and soare worthwhile.

The balance of this engine in the vertical direction is about as good asthat of an ordinary four-cylinder in-line engine, but it can be made asgood as that of a V-eight by adding a Lanchester balancer to cancel outthe secondary unbalance and by raising the countershafts a little tocompensate for the swinging of the connecting rod. In the horizontaldirections, the balance of the engine is theoretically perfect.

Theoretically perfect rotational balance of the engine is secured bymaking the sum of the moments of inertia of the two countershafts,countershaft gears, and counterflywheels equal to the sum of the momentsof inertia of the crankshaft, big end of the connecting rod, crankshaftgear, and generator rotor and half of the moment of inertia of thecamshaft and camshaft gear. Then, when the engine-and-generator isrunning, the algebraic sum of the moments of momentum of its movingparts will be zero, and their sudden accelerations caused by explosionsin the cylinder will be balanced in those moving parts and cause nomovement in the rest of the engine-and-generator. Hence the engine willrun without vibration.

The generator in this particular generating set is a Leece-Neville typeof high-frequency alternator with a multi-polar rotating field and withrectifiers so that its final output is direct current for use withstorage batteries, but any other type of generator may be used. It couldbe a four-pole alternator with either a permanent magnet or a woundrotating field and be run at 1800 rpm. to produce 60-cycle current. Forintermittent duty, the generator could have only two poles and the setcould be run at 3600 rpm. to produce 60-cycle current. For European use,the set could be run at 1500 rpm. or 3000 rpm. to produce 50-cyclecurrent.

The engine, instead of being a gasoline one, could be a diesel, in whichcase it might be desirable to increase the sizes of the crankpin,connecting rod, and countershaft drive gearing. The generating set thenwould be more suitable for use on boats having diesel main engines andon trucks and buses driven by diesel engines and for use in continuousservice.

The engine, instead of being a four-stroke-cycle one, could operate onthe two-stroke cycle, particularly if the generating set were intendedfor light duty or intermittent service, as in a house trailer, summercottage, or weekend yacht. If it were a two-stroke-cycle engine, itscrankcase should preferably be split in a plane perpendicular to theaxes of the shafts and passing close to or through the axis of thecylinder so that the interior of the crankcase could be made to enclosethe moving parts with small clearances. This is desirable in order toreduce the dead space in the crankcase, which acts as the scavengingpump in the usual manner. For a similar reason, the crankshaft should bemade with disc cranks, notched out at the sides of the crankpin justenough to provide balancing.

The generating set illustrated in FIGURE 3 consists of a one-cylindertwo-stroke-cycle horizontal diesel engine with a reciprocatingscavenging air pump and driving an electric generator through step-upgears.

In this engine, the crankshaft 31 has a single throw formed by the crankcheeks 32 and the crankpin 33, and, on each side of this crankthrow,there is an eccentric 34.

In this particular example (for the sake of simplicity of explanation),the eccentricity of the eccentrics is exactly half that of the crankpin,and the eccentrics are Spaced exactly 180 from the crankpin. At theouter sides of the eccentrics are the crankshaft journals 36 and 37.Beyond one of the journals, the crankshaft has a cylindrical portion 38that extends through a seal in the back of the crankcase and a taperedend that carries a flywheel 39. Beyond the other journal, the crankshafthas another tapered end that carries a large gear 40 and afuel-inject-ion cam 41, that may be made integral with the gear 40.

The crankpin 34 carries the big end of a conventional connecting rod 42,and the other end of the rod is connected to a piston 43 by a wristpin44 held in place by snaprings 45. The eccentrics 35 each carry aconnecting rod 46, whose little end is connected to a scavenging-airpump piston 47 by a wristpin 48, the two rods 46 being connected to theone large piston 47near'its sides and leaving a clear space at thecenter of the piston for the main crank throw and big end of the mainconnecting rod 42 to swing through. The wristpins 48 in the pump pistonare of hardened steel, but they are provided with button heads ofaluminum alloy that lit in counterbores in the sides of the piston.These heads have stems that are pressfitted into the bores of thewristpins, and they keep the wristpins from moving either in or out, thein-movement being prevented by the bottoms of the counterbores and theout-movement being prevented by the walls of the cylinder in which thepump piston 47 moves.

The cylinder in which the pump piston 47 moves is a conventional airpump cylinder with reed valvescontrolling the inlet and outlet, and itsdiameter is almost twice the diameter of the cylinder in which the powerpiston 43 moves. In the particular example shown, the power piston is3.5 inches in diameter, and the pump piston is 6.25 inches in diameter.Because of this large difference in diameter, the displacement of thepump piston, even though its stroke is only half as long as the strokeof the power piston, is about of that of the power piston, and enoughair is pumped to scavenge the power cylinder well. This air, however,cannot go directly from the pump cylinder to the power cylinder, becausethe phase relation is not right for that. Instead, a receiver isprovided in the air passage between the two cylinders to store the airbetween the time when it is pumped out of the pump cylinder and the timewhen it is admitted to the power cylinder. The power cylinder may be aconventional two-stroke-cycle one with loop scavenging and any suitabletype of combustion system.

The large gear 40 on the crankshaft drives a small gear 49 on thecounter shaft 50, which is formed with two journals 51 and 52, one nextto the gear and the other at the outer end of the shaft. Next to thejournal near the gear is the cylindrical portion 53 that passes througha shaft seal in the front Wall of the crankcase, which also forms thegearcase. The central-part of the countershaft has the rotor 54 of thegenerator pressed upon it, and the outer end of the countershaft isformed into journal 52 that is carried by the outboard bearing of thegenerator. In order to show it in the space available, most of thelaminations 56 of the rotor have been omitted from the drawing, but theends 57 and 58 of the windings and the commutator 59 are shown in theircorrect proportions.

The linear balance of this engine-generator set is simple and istheoretically perfect, with the exception of the negligible mass of theinjection pump cam follower and plunger. The two eccentrics balance thecrank throw, the exact balance being secured by adjusting the shape ofthe crank webs Where they extend along the inner sides of theeccentrics. The two pump connecting rods 46 weigh twice as much as themain connecting rod 42, and the pump piston and its wrist pins weightwice as much as the power piston 43 and its wrist pin, but they allbalance each other because the stroke of the power piston is twice 9 asgreat as the stroke of the pump piston. The working length of the pumpconnecting rods 46 is exactly half that of the main connecting rod sothe secondary unbalance of the pump piston, that has half the stroke ofthe power piston, will be exactly equal to the secondary unbalance ofthe power piston and will balance it exactly.

Rotational balance of the engine-generator is secured by making themoment of inertia of the crankshaft assembly exactly equal to the momentof inertia of the countershaft assembly multiplied by the ratio of thegears between them. In this particular example, the gears have 23 and 13teeth, so the flywheel 39 is made of such a size that the moment ofinertia of the crankshaft assembly is 23/13 or about 1.77 times that ofthe countershaft assembly.

This generating set is designed to run with the generator at 3600 rpm.and the engine at 2035 rpm. and to generate both alternating current at60 cycles per second and 110 volts and direct current at 12 to 14 voltsfor charging storage batteries. The generator is also provided withwindings that enable it to act as a 12 volt motor for starting thegenerating set. These characteristics and its vibrationless running makeit ideal for use in boats, house cars and house trailers.

For the sake of clarity of illustration, the countershaft 50 has beenshown in the same horizontal plane as the crankshaft. Actually, itshould be below or above this plane so that its inboard end will notinfringe on the space needed for the cooling water jacket and intake andexhaust passages of the power cylinder.

The combined engine compressor illustrated in FIG- URE 4 has one dieselpower cylinder, in which the power piston 71 operates, and first andsecond stage air compressor cylinders, in which the large and small aircompressor pistons 72 and 73 operate. These cylinders lie in ahorizontal plane passing through the axis of the crankshaft 74, to whichthe pistons are connected by connecting rods 75, 76, and 77. The bigends of all the connecting rods are split on angles of 45 so that theycan be withdrawn through the cylinders, and the crankpin on which thesecond stage com-pressor connecting rod 77 is mounted is smaller indiameter than the others so that that rod can be withdrawn through itssmaller cylinder.

The crankshaft 74 has five journals 78 to 82 supported by bearings inthe crankcase, and it overhangs these bearings at both ends. At one end,it passes through a seal in the end wall of the crankcase and carries aheavy flywheel 83 spigotted and bolted to it. At the other end, itcarries a small gear 84 that drives the camshaft gear 85 and thecamshaft 86 at half the crankshaft speed. The camshaft is located aboveand to one side of the crankshaft and carries inlet and exhaust cams 87and 88 and a fuel injection pump cam 89.

Between the two journals 78 and 79 near the flywheel end of thecrankshaft, the crankshaft is formed with an integral flange to which isbolted a large gear 91. This gear engages a smaller gear 92 on a sturdycountershaft 93, that extends out of the other end of the crankcase andcarries there a steel plate counter-flywheel 94 spigotted and bolted toa flange on its end. The countershaft is located above the crankshaftand on the other side from the camshaft, and it has three journals 95,96, and 97 by which it is supported in bearings in the crankcase. Theflange 98 on its end fits in a seal'in the wall of the crankcase.

This engine-compressor is in theoretically perfect linear balancebecause the air compressor cranks, connecting rods, and pistons are madeto balance the engine or power crank, connecting rod, and piston. Thetwo compressor crank throws 99 and 100 are spaced at equal distancesalong the crankshaft on opposite sides of the power crank throw 101 andare at 180 from it. One compressor crankpin'is but half the length ofthe power crankpin, and the other is much smaller in diameter, so

the combined weights of the two compressor crankpins is about equal tothe weight of the one power crankpin. Any difference in weight and theextra weight of the compressor crank cheeks is balanced by smallcounterweights 102 on the compressor cranks. Each compressor connectingrod 76 or 77 is made exactly half the weight of the power connecting rod75, and each compressor piston 72 or 73 is made exactly half the weightof the power piston 71.

The engine-compressor is in theoretically perfect rotational balancebecause the flywheel 83 and counter-flywheel 94 are made to balance eachother and all the other parts that rotate in the machine. Thecounter-flywheel 94 is much thinner than the flywheel 83 because it isgeared up relative to it, the gear ratio in this example being 41 to 15.The algebraic sum of the moments of inertia of all the rotating partsmultiplied by the speed of each part relative to the speed of thecrankshaft is made to be zero.

For the sake of simplicity of explanation, this engine compressor wasdesigned with equally-spaced equal throws of the crankshaft and withfirst and second stage compressor pistons and rod exactly half as heavyas the power piston and rod. All of these proportions can be varied andthe parts still kept in balance. The number of cylinders and theirarrangement may be changed; for example, the crankshaft could have asingle counterweighted crank, to which would be connected the pistons ofone power cylinder and one compressor cylinder at to each other. In thisform, the crankcase could act as a scavenge pump, and the power cylindercould operate on the two-stroke cycle.

Another invention, embodying the same principles as those alreadydescribed above and particularly analogous to those illustrated inFIGURES 3 and 4, is a portable engine-and-water-pump balanced so as tobe practically vibrationless and particularly useful in firefighting andmarine salvage operations. This machine consists of ahorizontally-opposed two-cylinder two-cycle engine of the type widelyused for outboard boat motors before it was realized that most of thevibration of such motors came from the simultaneous power impulses andnot from their dynamic unbalance. To the crankshaft of this engine isgeared a countershaft to run at the same speed as the crankshaft but inthe opposite direction, and this shaft is provided with a pair offlyweights like the flyweights 20 and 21 in the engine-generatorillustrated in FIGURES 1 and 2, but these flyweights are both on oneshaft and are from each other. Together with the counterweights on thecrankshaft, they balance out all of the primary unbalance of the pistonsand connecting rods, leaving only a secondary couple to cause a smallamount of vibration. The countershaft also carries, on the outside ofthe crankcase, the impeller of a centrifugal pump and acounter-flywheel, and the counter-flywheel is of such a size that themoment of inertia of the countershaft assembly is equal to the moment ofinertia of the crankshaft assembly, and hence the combined machine is inrotational balance, and the only vibration will be the slight one causedby the secondary unbalance of the pistons. The flyweights are preferablyin the planes of the two crank throws, and each balances out half of theprimary unbalance of the piston and small end of the connecting rod onthe crank throw in line with it; the other halves of these primaryunbalances are balanced out by each other and by the counterweights. Thecounterweights are big enough to also balance the parts of the Weightsof the crank pins and big ends of the connecting rods that are notbalanced by each other.

Still another invention, embodying the same principles as those alreadydescribed above and particularly analogous to the air compressor setillustrated in FIG- URE 4, is a power-gas generator. This is a machinethat produces hot gas under pressure, that can be fed to a turbine toproduce mechanical power. Free-piston engines have been used aspower-gas generators, but they are tricky machines and too complicatedfor use in small sizes. The present invention consists of a dieselengine balanced according to the principle disclosed in the first partof this specification and delivering its exhaust under pressure to aturbine. The engine could be a standard fourcycle diesel engine with adifferent camshaft that would operate the valves without overlap andwith a counterflywheel geared to the crankshaft so as to turn in theopposite direction and having the proper moment of inertia to satisfythe conditions explained in the first part of this specification.Alternatively, it could be a twocycle diesel engine of a standard typebut with a somewhat enlarged scavenging pump and with a counter-flywheelof the right moment of inertia geared to its crankshaft so as to turn inthe opposite direction. In either case, the exhaust pipe of the enginewould be connected to the inlet of a suitable turbine, which wouldconvert the gas power into mechanical power, and the counter-flywheelcould be connected to the crankshaft as it is in the engine-compressorillustrated by FIGURE 4. Alternatively, an engine like the one shown inFIGURE 3 could be used, the only change necessary being the substitutionof a simple counter-flywheel for the generator rotor. Another group ofinventions embodying the general principle disclosed in thisspecification are engines driving marine or aircraft propellers. Inthese, the power is applied as a thrust upon the water or air movingpast the vehicle rather than as a flow of electric current, gas, orliquid under pressure, as in the specific forms of the inventionsdiscussed above. One example of this group of inventions can be madesimply by taking the engine illustrated in FIGURES 1 and 2, replacingthe gefierator rotor 1 by a flywheel, connecting the crankshaft 2 to apropeller shaft and a propeller, and adjusting the sizes of the newflywheel and the counter-flywheels and 11 so that the moments of inertiaof the parts rotating in opposite directions will be in balance. Anotherexample can be made by taking the engine illustrated in FIGURE 3,replacing the generator rotor 54 by a counter-flywheel, connecting apropeller shaft and propeller to the countershaft 50, and adjusting thesizes of the new counter-flywheel and the flywheel 39 so that themoments of inertia of the parts rotating in opposite directions will bein balance. This example can be improved for many applications by firstchanging the ratio of the gears so that they step down the speed fromthe crankshaft and thus provide a reduction gear to the propeller shaft,and the countershaft and the propeller shaft can be made hollow so thatthey will accommodate the control rod for a variable-pitch featheringand reversing propeller. For small airplanes, the principle heredisclosed can be applied by taking a. standard airplane engine with asimple gear drive to the propeller, such as the Con tinental GO-300-Eengine or the Lycoming GO-435- C2B2-6 engine, and rebuilding the nose ofthe engine with a flywheel on the crankshaft immediately behind thereduction gears, the flywheel being of such a size that the moment ofinertia of the crankshaft assembly will balance that of the propellershaft assembly. It is essential, in getting this balance, that thereduction gearing be of the simple spur or helical type that makes thepropeller turn in the opposite direction from the crankshaft.

Another group of inventions embodying the general principle disclosed inthis specification are engines that deliver mechanical power throughsome device that eliminates or greatly reduces the vibration in thatpower and that have counter-flywheels geared to their crankshafts tobalance them rotationally. The device that smooths out the powerdelivered by the engine can be a hydraulic coupling, a hydraulic torqueconverter, an electromagnetic coupling, a resilient coupling, a twistyshaft, or anything else that will absorb quick fluctuations in torque.An example of such an embodiment of the invention is shown in FIG. 5. Inthis engine, the crank- 12 shaft 30 lies between two countershafts 31and 32', and it carries a bear 33' at its front end that meshes withsimilar gears 34 and 35' on the countershafts. These gears drive thecountershafts at the same speed as the crankshaft but in the oppositedirection.

The crankshaft is connected to a piston 36 by a connecting rod 37 andwrist pin 38, and the piston operates in a conventional cylinder in theconventional way The countershafts are placed as close to the crankshaftas possible in order to keep the volume of the crankcase small and getgood compr'ession'of the air in the crankcase for scavenging thecylinder, and each countershaft is cut away at 39' on the side oppositeits counterweight to provide clearance for the bolts on the lower end ofthe connecting rod as they swing around with the crank. Fuel is injectedinto the cylinder at the proper time in each cycle of operation by aninjection pump that is worked by a cam 40' on one of the countershafts.

The crankshaft carries a pair of counterweights 41 that balance theweight of the crank cheeks, the crank pin and the lower end of theconnecting rod and half of the weight of the upper end of the connectingrod, the piston, and the wrist pin. The countershafts carry littlecounterweights 42' that balance the other half of the weight of theupper end of the connecting rod, the piston, and the wrist pin. Withthis arrangement of counterweights, this little onecylinder engine isbalanced vertically and horizontally as well as an ordinaryfour-cylinder in-line engine.

For taking power from the crankshaft in a" steady flow, even though thepower is created intermittently by successive explosions, there is afluid coupling on the rear end of the crankshaft. The housing 43 of thecoupling is in two parts bolted together, and the front part is boltedto the crankshaft flange and carries a ring gear 44' for an electricstarter. Within the housing, there is a runner 45', and the runner andthe front part of the housing are shaped so as to enclose a toroidalspace between them. Within this space are a set of semicircular vanes46' fixed to the housing and another set of semicircular vanes 47' fixedto the runner. When the fluid coupling is operating, the vanes 46' inthe housing form a centrifugal pump that throws oil against the vanes47' in the runner and turns the runner. The runner is fixed to an outputshaft 48' with a flange that can carry a friction clutch or any othermeans for transmitting power from the engine.

The forward ends of the countershafts carry counterflywhecls 49' and50', and these are of such a size and mass that the sum of the momentsof inertia of all the parts turning with and vibrating with thecountershafts is equal to the sum of the moments of inertial of all theparts turning with and vibrating with the crankshaft. This includes thelower end of the connecting rod and some of the fluid entrained by theimpeller vanes of the fluid coupling. Thus this engine is in dynamicrotational balance in the same way as the first example described above,and the power impulses applied to the crankshaft will cause vibrationsonly in the shafts and the parts fixed to them and will cause novibration of the engine block and crankcase.

An additional embodiment of the invention is shown in FIGS. 6 and 7. Thecrankshaft of this engine is built up of separate pieces pressedtogether, and this permits the lower ends of the connecting rods 61" tobe made in one piece and have roller bearings. The rear end of thecrankshaft has an integral flange 62 to which one side 63 of a flexiblecoupling is fixed by capscrews. The other side 64 of the flexiblecoupling is similarly fixed to a drive-shaft 65' that delivers the powerof the engine to the load; it may, for example, go to the clutch,transmission, and driving wheels of a small automobile.

The central part of the flexible coupling isa short cylinder of rubber66 or similar material with its faces bonded to the two sides 63' and 64of the coupling, and there is no other connection between the two sides.The rubber permits the input side 63' of the coupling and :thecrankshaft and all the ot lferpartsiconnected to it 'to vibraterotationally with respectlto the output side 64"and'the drive shaft 65',and, at the same time, it

trahsrnits the power of theengine. The front end of thecrankshaftcarr'ies a'gear 67' thatfmeshes with a similar gear 68"on acountershaft 69'. This drives the counterfsliaft at crankshaft speed butin'the opposite direction and makes it vibrate rotationally in exact'synchronism with the crankshaft.

The forward end of the countershaft has a counter-flywheel 70f fixed toit, and one side of the recessed face weights on the countershaftcooperate with the counterweights 73 onthe crankshaft to balance theweights of the pistons 74' both statically and dynamically, except*for'the small unbalance caused by the changing angularity of theconnecting rods during the strokes of the pistons. Thus thistwo-cylinder engine is as well balanced vertically and horizontally asan ordinary four-cylinder engine' g To balance the engine rotationally,the moment of inertia of the 'countershaft and counter-flywheel assemblyis made equal to the moment of inertia of the crankshaft assembly,including the lower ends 61' of the connecting rods andhalf of theflexible couplingp' As a result of this, the total angular momentum ofthe moving parts of the engine, back to the center of the flexiblecoupling, adds up algebracially to zero. If the crankshaft turnsclockwise, its angular momentum is negative, and that of thecountershaft is equal to it but positive, and their sum is zero.

Another engine embodying the principles of the present invention isshown inFIGURE 8. It has four cylinders in line, in which the fourpistons 80 move, and they drive a crankshaft 81"throughconnectihg rods82. The rear end of the crankshaft carries a large-spur or helical gear83', which meshes with a smaller gear 84' fixed to a counter-flywheel85.

The crankshaft extends beyond'the counter-flywheel drive gears 83' andcar'riesa hydraulic torque converter of the'type that usually forms thefirst part of the automatic transmission of an automobile. The housing86' of the torque converter, the parts inside fixed to the housing, someof the liquidwithin the housing, and the starter ringgear 87' on theoutside of the housing all turn with the crankshaft and act as aflywheel that vibrates rotationally with the crankshaft.

The counter-flywheel rotates and vibrates ratationally in exactsynchronism with the crankshaft, but at a greater speed because of thestep-up in the gears 83' and 8-4'. The moment of inertiaof the counterflywheel assembly is smaller than that of the crankshaft and converterhousing assembly, and their ratio is the same as that of the gears.Hence, when the'engine'is running, the algebraic sum of the angularmomentum of all ther'otating parts is zero and remains'zero even whenexplosions in the cylinders cause those parts to accelerate quickly.

" Besides all 'of' the "applications of the invention described above,there are some ways in which the invention probably canbe'p'artlyappli'ed with some benefit. These are installations in whichthe crankshaft of the engine is only partly free tovibrate'independentlyofthe load orinwhich the thing-to "which the power is applied isitself'yieldingj'One example,'shoivn in FIG. 7, is a marineengine'driving' a 'propeller90 through a shaft which has someflexibi-lity;"here the propeller, turning in the water can vibratedosome-extent with the crankshaft 91", and also, the crankshaft is free tovibrate somewhat independently of its load because of the flexibility orthe propeller shaft. In this example of the invention, there is shownone form'of the Lanchester balancer mentioned above; It consists of apair'of'small counterweights 92' directly'under the centerof theengineand driven by 14 ashaft 93' and gears 94' and 95' so as to rotate attwice the speed of the crankshaft. Another example is an aircraft enginewith the propeller mounted directly on the crankshaft; here thepropeller forms a part of the crankshaft vibrating system, but the airon which it acts lets it vibrate with some freedom. A third example,shown in FIG. 8, is in an automobile having independently sprung rearwheels or a DeDion rear axle, the transmission 101' at the rear in aunit with the final drive and differential 102, and a torsionallyflexible propeller shaft 103 connecting the engine 104 to thetransmission. The clutch 105' can be at either end of the twistypropeller shaft 103. In all these installations, the crankshaft systemis somewhat free to vibrate independently of the load, and it isprobable that a great reduction in the vibration of the engine blockcould be eflfected by providing counter-flywheels as described above. Itmight be difficult to calculate the exact moment of inertia for thecounter-flywheels that would be best in these cases, so it might beadvisable to experiment with counterfiywheels whose moments of inertiacould be varied, as by bolting additional steel discs onto their faces.

In any case, in determining the best moment of inertia for thecounter-flywheels, the moments of inertia and the relative speeds ofevery rotating part in the engine should be considered. For example, ifthe engine is a four-cycle one with a camshaft turning at half the speedof the crankshaft, one-half of its moment of inertia (including itsdriving gear) should be substracted from the moment of inertia of thecrankshaft system if it turns in the opposite direction or added if itturns in the same direction. But, if the drive to the camshaft issomewhat flexible, as it is when the drive is by chain, somewhat lessthan onehalf of the moment of inertia of the camshaft and gears shouldbe counted.

There is one more group of inventions embodying the general principledisclosed in this specification, that should be described. These areengines with two crankshafts turning in opposite directions, flywheelson both crankshafts so that the engines are in rotational balance astaught in this specification, and some means of taking the power fromthe engine While permitting the crankshafts to vibrate rotationally.That means can be a single marine or aircraft propeller, a singlehydraulic coupling or torque converter, one or more air-compressorcylinders, a high-pressure exhaust-gas pipe leading to a turbine, aresilient coupling, a twisty shaft, or any similar device. The enginescan have the crankshafts at the top and the bottom and have opposedpistons in each cylinder, as in the Junkers Juno airplane diesels usedin the prewar German South Atlantic air mail service. They can have thecrankshafts side by side at the bottom with separate vertical cylindersfor the diflerent cranks, as in the British Ariel Square Four motorcycleengine. They can have the crankshafts side by side with the cylindersinclined towards each other and having common combustion chambers andwith a single fuel injection pump and nozzle for each pair of cylinders.In each of these engines, there are already two vibrating rotary systemsthat rotate and vibrate rotationally at the same speed and that haveapproximately the same moment of inertia; to the crankshaft of eachsystem should be added a flywheel, and the weights of the flywheelsshould be adjusted so that their moments of inertia will balance eachother and all the other masses fixed to or geared to the crankshafts, astaught in this specification.

I claim, as my invention and discovery:

1. In an engine having a single main power output shaft, such as acrankshaft, that turns in a given direction and to which periodic powerimpulses are applied when the engine is supplying power to a load, oneor more rotary masses drivingly connected to the power output shaft soas to turn in the opposite direction at speeds in constant proportion tothe speed of the power output shaft and to vibrate rotationally in phasewith the power inertia of all other masses in or on the engine that turnin the same direction as the power output shaft, including any part ofthe load fixed to the power output shaft, multiplied by the ratio oftheir speeds to the speed of the power output shaft.

2. In an engine having a single main powerfoutput shaft, suchascrankshaft, that turns in a given direction and to which periodicpower impulses are applied when the engine is supplying power to a load,the power output shaft having fixed to it a power transmitting elementfree to vibrate rotationally relative to the load, one or more rotarymasses geared to the power output shaft so as to turn in the oppositedirection but at the same speed, the total moment of inertia of thoserotary masses being approximately equal to the total moment of inertiaof the power output shaft and the other parts connected to turn with itin the same direction, including the power transmitting element fixed toit.

3. In combination, a reciprocating engine having a single main poweroutput shaft and a power transmitting mechanism having a power inputelement fixed to the engine power output shaft, the engine having atleast one mass drivingly connected to the output shaft so as to rotatein the opposite direction at a speed with a fixed negative ratio to thespeed of the output shaft, the algebraic sum of the moments of inertiaof all the moving parts of the engine and of the power input element ofthe power transmitting mechanism multiplied by the ratio of their speedsbeing approximately zero, and the power transmitting mechanism being ofsuch a type that the torque reaction on the power input element isindependent of its instantaneous acceleration.

4. A combination as defined in claim 3 and in which the powertransmitting mechanism is an electromagnetic device in which the torquereaction on the power input element is created by a magnetic field.

5. A combination as defined in claim 3 and in which the powertransmitting mechanism is a screw propeller.

6. A combination as defined in claim 3 and in which the powertransmitting mechanism is a resilient coupling.

7. A combination as defined in claim 3 and in which the power inputelement is a centrifugal pump rotor.

8. An engine assembly, including an engine with at least one poweroutput shaft, at least one power transmitting element fixed to at leastone power output shaft, and at least one other shaft drivingly connectedto turn in the opposite direction to one power output shaft at a fixednegative speed ratio, in which the algebraic sum of the moments ofinertia of all the moving parts, including all power transmittingelements fixed to or geared to any power output shaft, about any axis,multiplied by their relative speed ratios, is approximately zero.

9. An engine assembly as defined in claim 8 and in which the powertransmitting element is the rotor of an electrical machine.

10. Anengine assembly as defined in claim 8 and in which the powertransmitting element is a fluid impeller.

11. An engine assembly as defined in claim 8 and in which the powertransmitting element is the input element of a coupling of a type inwhich the torque transmitted is independent of the instantaneousacceleration of the input element.

12. An engine assembly as defined in claim 8 and in which the powertransmitting element is one side of a resilient coupling.

13. A machine for transferring energy in one direction or the otherbetween gas under pressure and an electrical circuit, comprising acrankshaft, at least one piston connected to the crankshaft, acountershaft geared to the crankshaft so as to rotate in the oppositedirection and at a fixed speed ratio, electrical machine rotor fixed toone of the shafts,'and a flywheel rnassfixedftoone of the shafts so thattl ie" sum ofthe' ts of, inertia; qf the counterfshaft and all other, parts'rotatmg; in the same direction rnultipliedjjythef ratio of theirspeeds t0. the speedvof the crankshaft is approximatelyvequaltdthe sumof the momentsof inertia of the crankshaft and all other parts rotatingin the saute direction. multiplied. hyfthe ratio of their speeds to thespeed of the crankshaft.

l4. An electric ,generating set .cornprising a single crankshaft, atleast one pistonijconnected, to the crankha a s a r grot n xed ha-sr nktl ft, v eas one 'countershaft gearejdlto the crankshaft so a e rotatein the opposite direction and at j a fixed speed ratio, and at least onecounter-flywheel mass fixed to at.least one countershaft, the sumr'gfthe moments of inertia of the countershafts and all-parts fixed, to themmultiplied by the ratio of their speed to the speed of the crankshaftbeing approximately equalto the sum of the moments of inertia of thecrankshaft and all parts fixed to it.

15. An electric generating set comprising, a single crankshaft, a singlepiston and connecting rod connected to the crankshaft, a generator rotorfixed to the crankshaft, a pair of countershafts lying. parallel to. andat either side of the crankshaft and'geared to the crankshaft so as torotate at thesame speed but in ,the opposite direction, counterbalancingmasses on. the crankshaft and countershafts for counterbalancing theWeight of the piston and connecting rod, and onev or morecounter-flywheels fixed to the countershafts, the sum of the moments ofinertia of the countershafts and allparts fixed to them beingapproximately equal to. thesum of the moments of incrtiaof thecrankshaft andall parts fixed toit.

16. A single-cylinder reciprocating machine that is almost completelybalanced in. all the six possible directions of movement, comprising asingle crankshaft, a piston and connecting rod connected to. thecrankshaft, apair. of countershafts at either side of the crankshaft andgeared to it to run in the opposite direction and at the same speed,counterweights on the three shafts for counterbalancing the piston andconnecting rod, and, a flywheel on at least one of the countershafts,the massesgand dimensions of the moving parts in the machine or fixed toits shafts being such that their center of gravity remains practicallyin a fixed position relative to the axes of the shafts and the algebraicsum of theirmoments of inertia about any axis is practically zero. I Ia,

17. A reciprocating. engine haying a crankshaft, a countershaft gearedto the crankshaft so as to turn in the opposite direction, one of thosetwo shafts extending out of the engine and forming apower output. shaftto which a power absorbing ortransrnitting member can be fixed, andflywheel masses fixed to theshafts and having moments of inertia suchthat thesum of the moments of inertia of the masses connected to turninthe same direction as the power output shaft multiplied by the ratioof their speed to the speed of the power output shaft is substantially,smaller than the sum of the moments of inertia of the masses connectedtoturn in the opposite direction multiplied by theratio of their speeds,to the speed of the powerl-outputshaft. w

18. A reciprocating engine havingonlyone crankshaft, the crankshaftextendingout at one endof the engine to act as a power output shaftto.which a .power.-absorbing or transmitting memberean be -fixed,a;,countershaft geared to the crankshaft so as toaturn in the oppositedirection and projecting, out beyondthe. crankshaft at-the other end ofthe engine, and a largefiywheel, fixed to the projecting part of thecountershaft and-overlapping the end of the crankshaft. v p

19. In an eng ne, .a single. mainpower shaft, power producing means thatapply rotative pulsatingforcesto said shaft to effect rotation of thelatter, supporting means for said main po\ver., shaft4and saidP0wcr.;1producing means whereby said supporting means tends to besubject to a reaction to said rotative pulsating forces, means coupledto said shaft for rotation in the opposite direction to that of theshaft and for vibration in phase with but in opposite angular directionto said single main power shaft for at least partially compensating saidsupporting means for said reaction to said rotative pulsating forces, aload, and means connecting said single main power shaft to the load fortransmitting torque to the load while absorbing at least some of thevibration to thus enable said rotatable massive means to at leastpartially compensate for the rotative pulsating forces.

20. In an engine having a single main power output shaft, such as acrankshaft, that turns in a given direction and to which periodic powerimpulses are applied when the engine is supplying power to a load, oneor more rotary masses drivingly connected to the power output shaft soas to turn in the opposite direction at speeds in constant proportion tothe speed of the power output shaft and to vibrate rotationally in phasewith the power output shaft but in the opposite direction, the sum ofthe moments of inertia of those masses multi plied by the ratio of theirspeeds to the speed of the power output shaft being approximately equalto the sum of the moment of inertia of the power output shaft and to themoments of inertia of all other masses in or on the engine that turn inthe same direction as the power output shaft, including any part of theload fixed to the power output shaft, multiplied by the ratio of theirspeeds to the speed of the power output shaft.

21. In an engine having a single main power output shaft, such as acrankshaft, that turns in a given direction and to which periodic powerimpulses are applied when the engine is supplying power to a load, saidengine including supporting means therefor subject to angular vibrationresulting from said periodic power impulses, one or more rotary massesdrivingly connected to the power output shaft so as to turn in theopposite direction at speeds in constant proportion to the speed of thepower output shaft and to vibrate rotationally in phase with the poweroutput shaft but in the opposite direction, the sum of the moments ofinertia of those masses multiplied by the ratio of their speeds to thespeed of the power output shaft being a substantial percentage of thesum of the moment of inertia of the power output shaft and the momentsof inertia of all other masses in or on the engine that turn in the samedirection as the power output shaft, including any part of the load orpower transmitting means fixed to the power output shaft, multiplied bythe ratio of their speeds to the speed of the power output shaft to thuseffect cancellation of at least a substantial percentage of the angularvibration of the supporting means that would otherwise result from saidperiodic power impulses.

22. An electric generating set comprising a single crankshaft having .acrank and two eccentrics at the sides of the crank, a power pistonconnected to the crank, a scavenging air pump piston connected to thetwo eccentrics and located on the opposite side of the crankshaft fromthe power piston, the ratio of the mass of the pump piston to the massof the power piston being approximately equal to the ratio of the throwof the crank to the throw of the eccentrics, a countershaft geared tothe crankshaft so as to rotate in the opposite direction, a flywheel onthe crankshaft, and a power converter element fixed to the countershaft,the ratio of the moment of inertia of the crankshaft and flywheel to themoment of inertia of the countershaft and the power converter elementbeing approximately the same as the ratio of the gearing of thecountershaft to the crankshaft.

23. A power plant comprising an internal combustion engine having twoshafts, mechanism for applying power impulses to at least one of theshafts, a rigid mechanism interconnecting the two shafts for making themturn in opposite directions at speeds that have a fixed ratio to eachother and for making them accelerate and decelerate together in responseto the power impulses, and flywheel means fixed to the shafts, and meansfor abstracting most of the power of the engine from one of the twoshafts without interfering with said acceleration and deceleration ofsaid shafts, the ratio of the moments of inertia of the two shafts andthe parts connected to them to accelerate and decelerate with them beingsubstantially the inverse of the ratio of their speeds.

24. An engine installation comprising an internal combustion enginehaving two shafts, mechanism for applying power impulses to at least oneof the shafts, a rigid mechanism interconnecting the two shafts formaking them turn in opposite direction at speeds that have a fixed ratioto each other and for making them accelerate and decelerate together inresponse to the power impulses, fiywheel means fixed to the shafts, anda power transmitting element fixed to one of the shafts and proportionedto transmit most of the power from the engine, the power transmittingelement being of a type whose rate of power transmission varies with itsspeed of rotation but not with its instantaneous acceleration ordeceleration, and the ratio of the moments of inertia of the two shaftsand the parts fixed to them, including the power transmitting element,being substantially the inverse of the ratio of their speeds.

25. A combination as defined in claim 3 and in which the power inputelement is the rotor of an electric generator and in which a crankshaftis the power output shaft.

26. A combination as defined in claim 3 and in which the power inputelement is the rotor of an electric generator and in which a crankshaftforms part of the mass connected to turn in the direction opposite tothe output shaft.

27. A combination as defined in claim 3 and in which the powertransmitting mechanism includes a compressor crank, cylinder, andpiston.

28. A combination as defined in claim 3 and in which the powertransmitting mechanism is a hydraulic coupling.

29. A combination as defined in claim 3 and in which the powertransmitting mechanism is a hydraulic torque converter.

References Cited UNITED STATES PATENTS 1,011,400 12/1911 Bergstrom 230561,205,895 11/1916 Hoyt 123192 2,019,026 10/1935 Spear et al. 1231952,248,423 7/1941 Buchi 60-13 2,394,904 2/ 1946 Fowler 230-56 2,406,4918/ 1946 De Waern 12356 FOREIGN PATENTS 476,209 12/ 1952 Italy.

WENDELL E. BURNS, Primary Examiner.

MARK NEWMAN, Assistant Examiner.

23. A POWER PLANT COMPRISING AN INTERNAL COMBUSTION ENGINE HAVING TWOSHAFTS, MECHANISM FOR APPLYING POWER IMPULSES TO AT LEAST ONE OF THESHAFTS, A RIGID MECHANISM INTERCONNECTING THE TWO SHAFTS FOR MAKING THEMTURN IN OPPOSITE DIRECTIONS AT SPEEDS THAT HAVE A FIXED RATIO TO EACHOTHER AND FOR MAKING THEM ACCELERATE AND DECELERATE TOGETHER IN RESPONSETO THE POWER IMPULSES, AND FLYWHEEL MEANS FIXED TO THE SHAFTS, AND MEANSFOR ABSTRACTING MOST OF THE POWER OF THE ENGINE FROM ONE OF THE TWOSHAFTS WITHOUT INTERFERING WITH SAID ACCELERATION AND DECELERATION OFSAID SHAFTS, THE RATIO OF THE MOMENTS OF INERTIA OF THE TWO SHAFTS ANDTHE PARTS CONNECTED TO THEM TO ACCELERATE AND DECELERATE WITH THEM BEINGSUBSTANTIALLY THE INVERSE OF THE RATIO OF THEIR SPEEDS.